Ask HN: What are the economics of data brokers?

I clicked a link to a news story on Africa News [0] and was shocked to see a pop-up telling me that they'd like to share my data with 797 "partners". That's a huge number to my eyes. Can any "insiders" share the economics of so many data brokers on a single site? Do they pay the site owners for the data? What about buying/selling/coordinating that data to one another? Who are the largest customers of the data brokers' "services"?

[0] https://www.africanews.com/